In several details my bike, which is only from 2010, does not match the Rohloff videos. The Rohloff manual that came with my bike seems to match the details of my bike, i.e. is different than the videos. At the bottom of the title page of my manual appears "WS 2.13E 2008-02".
One Rohloff video shows the shifter rubber grip sliding off as a separate piece from the actual cable pulley. On my bike the rubber grip and the cable pulley are one piece.
The Rohloff video that shows how to route the cables through the shifter... it shows some pieces that slide out of the shifter and into which the cable housing ends fit. On my bike those interface parts are screwed in. When those parts are removed, you can turn the shifter and see where the cable ends fit into the pulley. That business in the video about turning between 6 and 7 doesn't seem to apply.
I just left the existing cable housings on my bike and replaced only the cables. I wonder how often these parts need to be replaced.
On pg 110 of my manual, under Repairs: 3. Changing the grip rubber, there is a POINTER:
"The shifter cables have to be removed from the twist shifter first before it is possible to replace the rubber grip. Before the shifter cables are removed, the ends that were clamped in the female connectors (internal gear mech) or the cable pulley (external gear mech) must be cut so that the frayed ends of these cables to not damage the nylon liners when being removed."
Ooops, I didn't see this in time! My ends weren't too frayed so I hope they didn't do much damage! But anyway this pointer is good evidence that putting in a new cable doesn't usually require new cable housings.